Fluid-pressure device.



R. LIEBAU,

FLUID PRESSURE DEVICE. APPLICATION FILED FEB. 25,19l 0. RENEWED OCT.9,1912.

- Patented July 13, 1915 ZSHEETS-SHEET 1.

l r v 9 inn-Hailin l/VVENTOH By %4@M/Armmm WITNESSES R, LIEBAU.

FLUID PRESSURE DEVICE. APPUCATION man FEB/25.1910. RENEWED OCT. 9. 1912.

Patented July 13, 1915.

' shins-SHEET 2.

INVENTOR a a 3m v w W W. 7 9/ T 6 5 kwa Z U o H! 6 W 1 4 W H A 1 vRICHARD LIEBAU, OF WATERVLIET, NEW YORK, ASSIGN'OR TO THE WESTINGHOUSEAIR SPRING COMPANY, A CQRPQRATIOI'J OF PENNSYLVANIA.

rLUIn-ranssuan nnvrcn.

fipecification of Letters rat-e rl Application filed February 25, 191D,Serial No. 545,957. Renewed Gctnbcr 9, 1912. Serial No. 7%,855.

To all whom it may concern Be it known that I, RICHARD LIEBAU, a citizenof the United States, and resident of lVatervliet, in the county ofAlbany and State of New York, have invented certain new and usefulImprovements in Fluid- Pressure Devices, of which the following is aspecification.

My present invention relates to the class of devices disclosed in theapplication of George "Westinghouse, Serial No. 520,039, filed September28th, 1909, and Serial No. 545,854 of even date herewith. It is embodiedin a fluid compression cylinder parof use in other relations, theinvention has been devised primarily in connectioirwith automobiles, andthe general ob ect in view has been to embody the principles ofresilient support by an elastic compression naedium, such as air or gasin a practical, selfcontained, gas-tight compression device adapted toserve all the purposes of the "steel springs commonly used, and to com-"fbine therewith all the desirable features of a shock absorber, theentire device belng adapted to meet the exacting conditions and to standthe rough usage required in connection with automobiles, deliveryWagons,

trucks, railway rolling stoclnetc- I prefer to make the compressionmembars in the form of telescoping tubes with the smaller or inner tubeuppermost. The tubes are hermetically closed at the outer endsand theinner tube is provided. at the inneriend w ith peripheral packingadapted to form a fluid tight joint, and is internally contracted toform a relatively constricted passage, so that the flow of liquid to andfro between the fixed volume compression space in' thenpper cylinder andthe variable space-in the lower cylinder, is more or less throttled. Thefluid Within the cy1in-.

ltwill be understood that though capableder consists of a compressiblemedium such may escape therefrom, and in certain cases the pump may havea sufiicient capacity to draw a certain amount of air from the outsideof the cylinder in which case a relief valve may be arranged toautomatieallyreduce the internal pressure in case it increases above apredetermined desired value. In said prior. application the pump isoperated by relative movement of the parts of the compression device,the direct source of the power for the pump being derived from the flowof the fluid medium from the variable volume space to thefixed volumespace within the same. I

My present invention has for its object the provision-or", a pump forsimilar purposes but operated by mechanical connection with therelatively movable part so that the action of the pump is'moredirectand-positive than when the power is derived through flow of thefluid medium.

My pump may be employed to produce suction on the low pressure side ofthe packing of the sliding joint, either with or without anoilcollecting groove or the pump may be used to apply the suctionbetween two packings as described in said application Serial No.545,883, of. even date herewith. Some of the advantages resulting fromdriving the/pump through mechanical connection with the relativelymovable arts are that the stroke of the piston may e as long as the mostextreme movement ofthe compression device when operated on a load I andthe power, available is. very great being measured by the totalexpansion and compression efiorts applied upon the com pression deviceduring operation. These advantages appear in greatest degree duringperiods when the compression device is subject to extreme compressionand expansion thereby causing the pump to make a stroke 'stricted thecentral .cylindrical wall 15.

equal to the sum of the distances of the compression and expansionmovement on both sides of normal.

I may combine my form of internal pump with an external compression pumpsuch, for instance, as set forth in application of George Westinghouse,Serial No. 545,854: of even date herewith.

In the drawings Figure 1 is a vertical central section of the device innormal position of rest under load. Fig. 2 is a similar view of the sameparts ina position of extreme compression. Fig. 3 is a top-plan view-ofthe cylinder.

The lower cylinder 1 is hermetically closed at the bottom by screw plug2 formed with a discharge passage 3 which is normally closed by a screwplug 4. This cylinder provides the variable space 5, which is adapted tobe increased or decreased by up or down movements of the plungercylinderfi. The latter is provided at hermetic screw closure 7. As shownin the drawings, the lower end is. screw threaded at 8 to a lunger headprovided with a conuid passage.

The main packing of the plunger comprises a seat 11 for a cup washer 12,which is clamped thereagainst by a ring 13 carried by a screw member 14,screw threaded to The free edge of the cup washer is preferably cutsquare and is continuously spring pressed against the outer cylinderwall by seel spring expanding rings 16, 16, the latter being conedexteriorly. These rings are 0 sufficient power to maintain the free edgeof the cup washer continuously in perfect contact with the cylinderwalls. The annular space adjacent the free edge of the cup washer12,'including the space containing the expanding ring 16, is suppliedwith oil from the annular reservoir 17, 1.7, by duct 18, passing throughcup leather seat 11 cup leather 12 and clamping ring 13 thence throughduct 19. These ducts provide a continuous supply of oil filling all thespace adjacent the packing 12 and escape is prevented by means of thesupplemental packing 22 arranged below the main packing and held incontact with the walls of the cylinder by expanding the ring 23. Escapeof oil from the annular reservoir 17 18 revented by the wall 24, so thatan abun ant supply of oil will remain inthe reservoir, even/in case thenormal level of the oil is be low the normal position case the packingshould be lifted above the oil, as might happen in case a large part ofthe normal load was removed from the spring.

The means for applying suction to the sliding contact surfaces in therear of the main packing is arranged in the plunger head. This meansconsists of a pump ing edges may the upper end with a of the packing, orin having an intake 25 extending ative relation to the inner wal 1. The

of cylinder intake is preferably supplied through an annular recess orchamber 26 formed or provided with thin edges 26 and 26, adapted toclear the outer walls of the cylinder from surplus oil. These clearbe ofrigid, resilient or yielding material. The intake is provided with acheck valve 27 of any known or desired construction and from this valvethe passage 28 leads to the pump cavity 29, whence the oil is dischargedthrough the outlet valve 30 and passage 31"leading to the interior ofthe cylinder.

According to my invention the pump cavity is formed in an upwardextension 32 carried by and preferably formed integral with the plungerhead and preferably stiffened or stayed by means of a web 33 which maybe cast integrally with the plunger and extension. The proportion ofparts must besuch that the pump piston will not be withdrawn from, thecavity even at the end of the longest possible suction stroke when thedevice is fully expanded and must notstrike forcibly against the end ofthe pump cavity at the end of the longest possible expelling stroke whenthe device is .fully compressed.- Hence, in the form shown the length ofthe pump cavity is approximately equal to the total possible relativemovement of the parts of the compression device from extreme expansionto. the extreme compression. The piston 34 is reeiprocated by means ofpower derived directly from relative movement of the parts of thecompression derice rather than through flow of fluid through theconstructed passage between the fixed volume and variable volumecompression spaces. A simple connection for this purpose is shown in thedrawings, the stem of the piston being provided with an annular shoulder36 engaging the correspondingly shaped retaining ledge 37 secured to thecylinder head 2. The connection at this point is preferably loose so asto permit the stem of the piston to shift to set itself in exactalinement with the pump on vitv especially during extreme compression ofthe device.- If the piston stem were fixed at this point the mostextreme accuracy of c nstruction and operation would be necessa 'y inorder to prevent lateral strains when the device is compressed to theposition shown in Fig. 2.

By reference to Fig. 1, which shows the device in normal position underload, it will be seen that the intake communicates with the pump cavityat a point about half way between the piston head when in normalintermediate iosition and the outlet at the extreme en of the longestpossible expelling stroke. If desired. however, the intake may bearranged at a lower point and may into opermasses piston when in -,theposition shown in Fig. 1.'

I In the normal operation of the device 'whenl'in use .for instance as aspring sup port on an automobile, the pumpcylinder being carried by theplunger head and the 7 pump piston being carried by the lower cylinderthe relative movement of the pump piston andcylinder will be greatestand most efficient "when the device as a Whole is subject to thegreatest compression and ex-' pension; For instance, when thehbtomo-'bile' passes over a sufiiiciently high obstruction at sufficient speedthe relative-movement will carry the pump 'piston'through the ex tremcrange of the expelling stroke and the pump cavity will be em tied bydischarge through the valve 30. 11 the recoil from such extremecompression the relativemovemeat will caose suction, tending to create avacuum until the intake 28 is uncovered at which instant the vacuum thusproduced will be available for applying a powerful instantaneous suctionon the intake. If the relative movement in the same direction iscontinued, the suction will be continued and increased until the extremeend of the suction stroke has been reached.

It will be noted that all lesser movements or the spring will beproportionately less eiiicient and some of the slower movements benormally covered by the I may be insuilicient toproduce any adequate v.suction on the intake orany adequate com;-

pression on the discharge valve. Nevertheless it is foundfin actual jractice that grea Ipovver and long stroke o' the pump render it soeiiicicnt that af satisfactory' amount of the pumpin operation isproduced even where the me movements occur onl at considerable intervalsas when procee ing i at relatively low speeds onicomparatively smoothre;

.i prefer to arrangean exterior or guardl cyhnder 5" screwed to'theclosure of the- .L as cylinder and engaging'the outside of cylinder l atthe-thickened annular edge 52: lover passages. The thickened annularedge is preferablyprovided with a cushion or sizing 54 adapted toperform a bun-er whenever; the comthe functi'. pression stroke issuificiently violent, to dr' e the flange of closure 7 down intocontherewith. The annular space 56 above sh in may be utilized as aircompreshich air compressed by the may be utilized to maincressuregreater than atmosi annular space 26- The enspace between the thickenedannular 52 the lower packing 53 maybe. zed thecompression space;amlspealas-constructions adapted for sucli operaation are described inthe" application'gof Westinghouse Serial Number-'5 s5g5i-li and 5%,854;oi": lats herew th andjsuch' 'is conventionally indicated at 40.

' cent walls. of cylinders 6 and 51. The part arrangements are not in.my invention except when usedm connection with the special form of pumpabove described, in

which case the exteri or pump sucks and such an arrangement extensivemovements of the spring serve to draw air in through,

the cheek valve while return movement compresses it and'whenthe movementis suiiicient to cause asufiicient rise in pressure the air tends toescape downward throughthe packing and through the joints between theannular enlargement 52 and the adjathat passesbetween 52 and 6 passesinto the 7 annu ar chamber 26 and raises the pressure thereby tending toforce oil or air or both up through the valve 27. It will be noted thatthisis most likely to happen at a time when the inlet 28 is covered bythe piston 34 so that the movement of materml from above valve. 27 intothe pumpcavity 29 upon downward movement of thelpiston is assisted bothby the external pressure-derivedfrom space 56 and bythe internalvacuum'due to downward movement of the pump pistonB-l. If the pressurederived.

from space 56 is insufficient to open the valve '27 it will neverthelessassist the'action of, the internal pump by causing air and oil .intheusliding ]oint between, 52 and 6, to

move toward the annular groove 26 thus keeping the joint clean and alsopreventing tendency to formation of a vacuum in chamher26.

' Obviously the tendency of the compressed air in 56 to escape between52- and 6 may be made greater than the tendency to escape between 52 and51, asjfor instance, by grooving the outersurface of cyiinder 6 as at 4dor byprovicling special packing between 52 and 51 or by both expedients.v

The arrangements for charging the device with oil and compressed airare'prefefably located in head 7 of cylinder 6. As shown in Fig, 1, aninlettube 60 extends down a desired distance, so that its outlet orifice61 is at or aboutthe desired level of the liquid] to be used. The assage,ofi air'or 12a liquid through this tube 1s controlled bye needle valveindicated at 62. As indicated.

[in Fig. 3,,thsre is a passage 64 leading from needle valve 62 may bemerely loosened and the oil supplied through the opening 66 and checkvalve 65. After oil has been charged into the device to a suitableheight, which is preferably above the level of the orifice 61 of pipe60, the compressed air is introduced through 66, 65, 64, 60, until theinternal pressure is sufiicient to support the described above issuflicient to raise the internal pressure of the device, undue raise ofpressure may be prevented by an automatic relief valve, which isdiagrammatically indicated in Fig. 3 as comprising a plug valve 70,closing spring 71, and screw adjusting means 72for adjusting the initialpressure of the spring to thereby predetermine the maximum internalpressure, which may be maintained in the device.

The annular collecting groove or chamber 26 is preferably ofconsiderably greater liquid capacity than would be necessary when thedevice is in continuous use and the pump in more or less continuousoperation. With a groove of the size shown, the device may stand forlong periods under very heavy loads and considerable oil may leakthrough the main packing without the possibility of any oil passingabove said collecting groove, which forms a break in the capillary pathbetween the close fitting surfaces of the two cylinders, which break canonly be bridged by complete filling of the collecting space. It willthus be evident that up tothe capacity of the latter space, the deviceis proof against ultimate loss of oil or internal pressure, because all.oil contained in "uch space will be returned to the interior of thecylinder by the pump as soon as the latter is put in action by thereciprocating movements of the parts, attendant uponaiormal active usethereof.

The reservoir oil space 17 is out of the direct path of to and fromovement of fluid, and, hence, the main body of the oil may be churnedinto foam to a considerable depth while a body of relatively undisturbedoil will remain to cover the ducts 18. Moreover, any foam above thelevel of 24 will constitute a source of replenishment for reservoir 17by reason of the oil which will settle out of the foam and flow downinto said reservoir. Theliquid used is preferably pure, free flowing,mineral oil and it may be mixed with pure, perfectly pulverizedgraphite.

I 1,14a,aaa

The above described device is rovided at both ends with journals 80, 80,a apted to engage pivots of a universal joint comprising pivots arrangedat right angles to each other and a cooperating bracket attached to oneof the members to be cushioned by said 7 device. I

Various features of m invention are adapted for use in other re ationswhere the conditions and functions to be servedare similar, as, forinstance, in other devices wherein a sliding joint is required tosustain great pressures without leaking; also they a sliding jointtherebetween and forming a chambered device capable of movement forcompression and extenslon, of liquid and gaseous fluids within thechamber, and 'a. pump within said chamber having mechanical connectionwith both of said members for transferring leaked liquid to saidchamber.

2. The combination with members having .195

a sliding joint therebetween and formin a.

chambered device capable of movement or 'v compression and extension, ofpacking for said sliding joint, liquid and gaseous fluids within thechamber and a pump within said chamber having mechanical connection withboth of said members for transferring leaked liquid from the lowpressure side of said packing. to said chamber.

3. The combination a sliding joint therebetween and forming a chambereddevice capable of movement for compression and extension, liquid andgaseous fluids within the-chamber, and a pump having a piston and a pumpcavity one of which is connected with each of said members and theoperation of which is dependent upon the compression and extensionmovements, for pumping liquid into said chamber.

with members having 4c. The combination with members having a slidingjoint therebetween and forming achambered device cap-able of movementfor compression and extenslon, a[cons trict 'on within said chamberbetween its ends, anda pump within said chamber oneelement of which isin positive connection with'one member, and the discharge of 'whichconnects with saidchamber. 4

5. A cushion device comprising relatively movable members forming achamber and having a slidingjoint-therebetween to permit variation ofthe volumetric capacity theneof; liquid and gaseous fluids within saiddevice, and a p'umpwithin said device each element of whichismechanically connected to one-of said members and having atisse itsdischarge connected With said chamber whereby liquid Which has leaked bysaid joint is transferred to the interior of the device.

'6. A cushion device comprising relatively movable members forming achamber and. havinga sliding joint therebetween to perinit variation ofthe volume of the fluid contained therein; liquid and gaseous fluidswithin said chamber, and a. pump located within said chamber positivelyconnected to one of said members and actuated by the other 'of saidmembers to pump fluid into said chamber.

7 A cushion device comprising relatively movable members forming achamber and having a sliding joint therebetween to per-- mit variationof the volume of the fluid con-. tained thereimoliquid and gaseousfluids within said chamber, and means, a portion of ivhich ismechanically, connected to each or said members, for forcibly returningescaped fluid into said "chamber.

Q. A cushion 'device comprising a cylinder, a plunger fitted -to'slidewithin said cylinder, a main packing for the sliding joint" betweensaid-plunger and cylinder, and a supplemental packing adjace'iit-saidmain packing on its high pressure side closing in anfoil space betweenthe main and supplemental packings, in combination with a collectingchamber for oil on'the low pressure I side of the main packing, andmeans employingmembers positively connected to said cylinder and plungerfor applying sue: tion to said collecting chamber.

9. A cushion device comprising a cylinder {a plunger fitted to slidetherein, a packing for the sliding joint between said plungerand'cylinder, an oil reservoir adjacent said packing on its highpressure side for retainingoil in contact with said packing, a chamberfor collecting the oil passing said packing and a pump mechanicallyconnected to said cylinder and plunger for transfer-ring oil from saidcollecting chamber into said cylinder;

10. A cushion device comprising relatively movable members forming aclosed chamber having a sliding joint, and a pump, the elements of Whichare positively connected with said members, and having an outletconnection with said chamber.

11. A cushion device comprising relatively movable members forming aclosed chamher, having a sliding joint, an oil collecting chamber, anagent for transferring oil from collecting chamber to said closedchamher, and means for positively connecting the separate elements ofsaid agent to the separate members and for thereby utilizing therelative movement of said members for operating said agent.

12. A cushioning device comprising telek fit scoping members inclosing achamber, a

pump located Within said chamber aiid lie-v the packing, one of theelements of said means being mechanically connected'to one of saidmembers, and the other element of said means to the other member.

14. A cushioning device including relatively movable members for varyingthe volumetric capacity of'a chamber formed With-- in the device, a pump'for transferring liq- .uid contained Within the device and having oneelement thereof mechanically connected to one of said members and theother element mechanically connected to the other member.

15. In a cushioning device, relatively mov able members for varying thevolumetric capacity of a chamber formed within the device, a pumplocated Within the chamber and mechanically connected to said membersfortransferring liquid contained Within the chamber, and a second pumpactuated by the relative motion of the members for re turning leakageliquid back into the chamber.

16. A. cushioning device comprising telescoping members having a slidingioint and including a chamber adapted to contain an expansible and anon-comprcssible fiuid a packing for said joint, means located Withinthe chamber and positively actuated by the telescoping members fortransferring noncompressible fluid from the bottom thereof to saidpacking, and means actuated by the relative motion of the members forreturning liquid leaking past the packing back into the chamber. I

17. In a cushioning device, relatively mov- I able members for varyingthe volumetric capacity of a chamber inclosed by said members, a packingfor the sliding oint between said members, means positively actuated bythe relative motion between said members forwconveying liquid Withinsaid chamber, and means for forcing air into said chamber.

18. A cushioning device comprising telescoping members having a slidingjoint and inclb'sing a chamber, a packing for the joint, a pump locatedWithin the telescoping; members and positively actuated thereby fortransferring leakage liquid from the low pressure side of said packingback into the chamber, and leakage liquid collecting means. located onthe outside of said telescoping member's and tommunicating vvith theintalieof said pump.

19. In a cushioning device, relatively movablemembers having a slidingjoint therebetween for varying the volumetric capac ity of a chamberlocated within the device, a packing for the sliding joint, a leakagecolecting passage located outside of the chamber for collecting liquidleaking past the packing, and means located within the chamber,positively actuated by said members, and communicating with said passagefor returning the liquid back into the cham-.

ber.

20. In a cushioning device, relatively movable members having a slidingjoint therebetween for varying the volumetric capacity of a chamberlocated within the device,

'a acking for the sliding joint, a leakage ed to said separate membersfor returning "liquid leaking past the packing back into said chamber,and means located outside of said chamber and operating in series withsaid pump for delivering leakage liquid back into the chamber.

22. In a cushioning device, relatively movable telescopic members havinga sliding joint therebetWeen and inclosing a chamber, a packing for saidsliding joint, a leakage collecting space formed within the chamber onthe low pressure side of the f-packing, a'pump, having its separateelements positively connected to the separate telescoping members forreturning liquid from said passage into the chamber, a guard cylindersurrounding the telescoping members and forming a leakage collectingpassage, and means cooperating with said cylinder for forcing theleakage liquid back into said first-mentioned collecting space.

In a cushioning device, relatively movable members for varying thevolumetric capacity of a chamber located within the device and having asliding joint therebetween, and means positively connected to saidmembers and actuated by the "relative motion of said members for forcingair into said chamber.

24. An elastic compression device, comprising relatively movable membersfor I varying the volume of the elastic fluid contained in said device,in combination with a pump having a cylinder mechanically connected withone of said movable members and a piston mechanically connected with theother of said members and arranged to decrease the pressure on the lowpressure side of the sliding joint between said members.

25. An elastic compression device, comprising relatively movable membersfor varyingthe volume of the elastic fluid contained in said device, incombination with an internal pump having a cylinder mechanicallyconnected with one of said movable members and a piston mechanicallyconnected with the other of said members and arranged to increase thepressure within the pressure cavity of said device.

Signed at New York in the county of New York and Stateof New York this14th day of February A. D. 1910.

RICHARD LIEBAU.

Witnesses:

GEORGE C. DEAN, IRVING M. OBRIEGIIT.

